Cyanotype is a photographic printing technique, made using sunlight, that results in a cyan-blue print.
The process was discovered in 1842, and has been widely used by artists and photographers, but also engineers, as a way to create affordable copies o
                  
       
           
               
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                